Fluid interface device as well as apparati and methods including same

Abstract

A fluid interface device, such as an airfoil assembly, can include a device structure and at least one movable band oriented such that the band moves in a direction of fluid flow. The at least one movable band can be supported on the device structure such that an outer surface of the movable band is exposed along the device structure and is capable of movement relative thereto such that a relative velocity can be maintained between the outer surface and the device structure. The fluid interface device can also include an edge extension disposed along the leading edge of the device structure. An airplane, a wind turbine and a method are also included.

The invention claimed is: 
     
       1. An airfoil assembly for use in a gaseous fluid, said airfoil assembly comprising:
 an airfoil structure having a longitudinal length and including a first longitudinal edge, a second longitudinal edge spaced laterally from said first longitudinal edge, a first side extending longitudinally along at least a portion of said longitudinal length between said first and second longitudinal edges, and a second side extending longitudinally along at least a portion of said longitudinal length between said first and second longitudinal edges and generally opposite said first side; and, 
 a fluid interface device operatively associated with said airfoil structure, said fluid interface device including:
 a movable band having a width and supported on said airfoil structure such that at least a portion of said movable band is exposed along at least one of said first and second sides of said airfoil structure; and, 
 an edge extension positioned along said first longitudinal edge of said airfoil structure and supported on said airfoil structure for rotational movement about a longitudinal axis extending along and internally within said airfoil structure such that the position of said edge extension is rotatable about said longitudinal axis relative to said airfoil structure, said edge extension including a third longitudinal edge and being positionable upon rotation of said edge extension about said longitudinal axis into approximate alignment with at least a portion of said movable band such that relative movement between said airfoil assembly and a gaseous fluid results in a gaseous fluid flow across said airfoil assembly with said third longitudinal edge of said edge extension functioning as a leading edge of at least a portion of said airfoil assembly. 
 
 
     
     
       2. An airfoil assembly according to  claim 1 , wherein said movable band includes an outer surface, said movable band oriented such that said width extends longitudinally along said airfoil structure, said movable band supported on said airfoil structure such that said outer surface is exposed along at least a portion of at least one of said first and second sides of said airfoil structure and is supported for lateral movement along said at least one of said first and second sides such that a relative velocity is maintained between said outer surface and said at least one of said first and second sides of said airfoil structure. 
     
     
       3. An airfoil assembly according to  claim 1 , wherein said edge extension has a longitudinal length and extends lengthwise from a first end to a second end that is spaced longitudinally from said first end, said edge extension being supported along said airfoil structure such that said edge extension extends along said first longitudinal edge of said airfoil structure and spans at least said movable band across said width thereof. 
     
     
       4. An airfoil assembly according to  claim 1 , wherein said edge extension has a cross-sectional shape and in cross section includes a first wall portion, a second wall portion extending from along said first wall portion and a third wall portion extending between and operatively interconnecting said first and second wall portions to at least partially define a hollow construction of said edge extension. 
     
     
       5. An airfoil assembly according to  claim 1 , wherein said first and second wall portions at least partially define said longitudinal edge of said edge extension. 
     
     
       6. An airfoil assembly according to  claim 1 , wherein said fluid interface device includes an actuator connected to said edge extension and operative to selectively displace said edge extension about said longitudinal axis. 
     
     
       7. An airfoil assembly according to  claim 1 , wherein said edge extension includes a first extension surface and a second extension surface disposed at an acute angle relative to said first extension surface such that said edge extension has a wedge-shaped cross-section. 
     
     
       8. An airfoil assembly according to  claim 7 , wherein a reference plane extends lengthwise along said airfoil structure and is oriented in tangential relation to a feature of at least one of said airfoil structure and said movable band, said third longitudinal edge of said edge extension is a forward edge, and said edge extension includes at least one rearward edge extending longitudinally along said edge extension in laterally spaced relation to said forward edge, said at least one rearward edge disposed in offset relation to said reference plane. 
     
     
       9. An airfoil assembly according to  claim 8 , wherein said edge extension includes a first rearward edge and a second rearward edge disposed in spaced relation to said first rearward edge with said first and second rearward edges disposed in offset relation to said reference plane. 
     
     
       10. An airfoil assembly according to  claim 7 , wherein a reference plane extends lengthwise along said airfoil structure and is oriented in relation to a feature of at least one of said airfoil structure and said movable band, and at least one of said first extension surface and said second extension surface is disposed at an acute angle relative to said reference plane. 
     
     
       11. An airfoil assembly according to  claim 10 , wherein said reference plane is disposed in approximate alignment with a portion of said movable band disposed along said second side of said airfoil structure. 
     
     
       12. An airfoil assembly according to  claim 10 , wherein said first extension surface is disposed at an angle relative to said reference plane with said angle having a value within a range of from approximately 1 degree to approximately 5 degrees. 
     
     
       13. An airfoil assembly according to  claim 10 , wherein said second extension surface is disposed at an angle relative to said reference plane with said angle having a value within a range of from approximately 20 degrees to approximately 70 degrees. 
     
     
       14. An airfoil assembly according to  claim 7 , wherein said third longitudinal edge of said edge extension is formed adjacent a constructive intersection of said first and second extension surfaces. 
     
     
       15. An airfoil assembly according to  claim 14 , wherein said first longitudinal edge of said airfoil structure has an edge curvature that has a value, and said third longitudinal edge of said edge extension has a cross-sectional profile with an extension curvature that has a value that is 20 percent or less of said value of said edge curvature. 
     
     
       16. An airfoil assembly according to  claim 15 , wherein said value of said extension curvature is approximately 5 percent or less of said value of said edge curvature. 
     
     
       17. An airfoil assembly according to  claim 1 , wherein said fluid interface device is one of a plurality of fluid interface devices disposed in longitudinally spaced relation to one another in a lengthwise direction along said airfoil structure. 
     
     
       18. An airfoil assembly according to  claim 1 , wherein said fluid interface device includes a plurality of movable bands disposed in longitudinally spaced relation to one another in a lengthwise direction along said airfoil structure. 
     
     
       19. An airfoil assembly according to  claim 18 , wherein said edge extension has a longitudinal length and is supported along said airfoil structure such that said longitudinal length of said edge extension spans two or more of said plurality of movable bands. 
     
     
       20. An airfoil assembly for use in a gaseous fluid, said airfoil assembly comprising:
 an airfoil structure having a longitudinal length and including a longitudinal axis extending lengthwise along and within said airfoil structure, a first longitudinal edge extending longitudinally along said airfoil structure, a second longitudinal edge extending longitudinally along said airfoil structure and spaced laterally from said first longitudinal edge, a first side extending longitudinally along at least a portion of said longitudinal length between said first and second longitudinal edges, and a second side extending longitudinally along at least a portion of said longitudinal length between said first and second longitudinal edges and generally opposite said first side; and, 
 a fluid interface device operatively associated with said airfoil structure, said fluid interface device including:
 a movable band having a width and supported on said airfoil structure such that at least a portion of said movable band is exposed along at least one of said first and second sides of said airfoil structure; and, 
 an edge extension positioned along said first longitudinal edge of said airfoil structure and supported on said airfoil structure for rotational movement about said longitudinal axis internal to said airfoil structure such that said edge extension is rotatable about said longitudinal axis between a first position in which a first surface of said edge extension is disposed in approximate alignment with said first side of said airfoil structure and a second position in which a second surface of said edge extension opposite said first surface is disposed in approximate alignment with said second side of said airfoil structure, said edge extension including a third longitudinal edge facing away from said movable band such that relative movement between said airfoil assembly and a gaseous fluid results in a gaseous fluid flow across said airfoil assembly with said third longitudinal edge of said edge extension functioning as a leading edge of at least a portion of said airfoil assembly.